Rick Wakeman - Journey to the Centre of the Earth (1974)

Ah, this brings backs loads of good memories! We used to gather at my house now and again to blast it on my JVC quadraphonic system (we were already enjoying surround sound way back in the '70s, y'all!).

'Journey' may sound a bit dated and overwrought to some ears now, but it's the quintessential sound of narrative-based '70s symphonic rock.